Current-regulator.



No. 746,669. PATENTBD DEC, 15, 1903.

" G. ARGARDWELL.

CURRENT REGULATOR.

APPLICATION FILED-MAR. 21. 1903.

N0 MODEL. 4 SHEETS-SHEET 1.

" 3 ZQWW a m L No. 746,669 PKTRNTRD DEC. 15, 1903'. G. A. GARDWELL.

CURRENT REGULATOR.

APPLICATION FILED MAR. 21, 1903.

R0 MODEL. 4 SHEETS-SHEET 2.

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PATENTED DEC. 15, 1903.

G. A. GARDWELL.

CURRENT REGULATOR.

APPLICATION FILED MAR.21,1903.

no MODEL.

4 SHEETS-SHEBT 3.

I j 4 V/ XETLRS cu. IMOID-LHHLI. WASHINGTON D c No. 746,669. PATENTED DEC. 15; 1903.

' G. A. CARDWELL.

CURRENT REGULATOR.

APPLICATION FILED MAR. 21, 1903. H0 MODEL. 4 SHEETS-SHEET 4.

llllllll lllllllllllllllllll IIIII IHIII IYIIIII (31X) Q0 mm/wboz UNITED STATES Patented December 15, 1903.

PATENT OFFICE.

GEORGE ALEXANDER CARDWELL, OF NEYV YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO INTERNATIONAL ELECTRIC CONTROLLER COMPANY, A CORPORATION OF NEIV YORK.

CURRENT-REGULATOR.

SPECIFICATION forming part of Letters Patent No. 746,669, dated December 15, 1903.

Application filed March Zl, 1903. Serial No. 148,926. (No model.)

To aZl whom it may concern.-

Be it known that I, GEORGE ALEXANDER OARDWELL, a citizen of the United States, and a resident of the borough of Manhattan, city, county, and State of New York, have invented certain new and useful Improvements in Current-Regulators, of which the following is a specification accompanied by drawings.

This invention relates to current-regulators, and its objects are to improve and simplify such devices and increase their efficiency of operation, so that the regulator is adapted for purposes more particularly hereinafter set forth.

Current-regulators have heretofore been devised in which the currentis rapidly made and broken and the length of the time intervals during which current flows is varied; but it is difficult to prevent sparking in this class of device, especially on an inductive circuit.

According to the present invention the circuit is never actually broken, but the length of the time intervals during which currents of predetermined strength flow is varied without breaking the circuit. Suitable means are provided for enabling maximum and minimum currents to be obtained in the regulator-as, for instance, by gradually introduc ing resistance into circuit up to a maximum amount for practically cutting off the current entirely.

Further objects of the invention will hereinafter appear; and to these ends the invention consists of apparatus for carrying out the above objects, embodying the features of construction, combinations of elements, and arrangement of parts, having the general mode ofoperation substantiallyas hereinafter fully described and claimed in this specification and shown in the accompanying drawings, in which-- Figure 1 is a side elevation, partly in section, of apparatus embodying the invention. Fig. 2 is a plan view of the same, partly in section. Fig. 3 is an end View, partlyin section. Fig. 4 is a vertical transverse sectional View of the regulator with the motor-shaft and brushes removed. Fig. 5 is a face view of the movable plate of the regulator; and Fig. 6 is a diagrammatic plan view of the apparatus, showing the general arrangement of circuits.

Referring to the drawings, A represents a suitable base, upon which is mounted a motor B, having a shaft 0 for operating the regulator. The motor B may be supplied with current in any suitable and usual manner, as shown in Fig. 6 the positive and negative supply leads for the motor being led to suitable binding-screws, which may be situated on the motor-frame. In this instance a disk D is slidably mounted upon the base A, while brushes E are adapted to be rotated by means of the motor. The brushes bear upon the disk D, which is of conducting material, and said brushes are electrically connected in pairs by means of the springs F. The arms Gr, provided with the brush-holders H, are carried by the motor-shaft O and suitably insulated therefrom, while the springs F are also insulated from the motor-shaft.

The disk D, as shown, is provided with the segmental portion I, insulated from the main portion J of the disk by means of the insulating material K, in which is embedded the conducting-strips L at one side of the segment I. At the other side of said segment are embedded the conducting-strips O, P, Q, and R for a purpose hereinafter to appear.

As stated, the disk D is slidably mounted for movement in a longitudinal direction, or, that is, transversely to the motor-shaft, any suitable means being provided to afford provision for the movement of the disk as specified. Upon the standard S, secured to the base A, are provided the Ways T for the slides U upon the back of the disk D, and the disk is provided with a rack V, with which a pinion N cooperates, so that by turning the hand-wheel X, connected to the pinion and mounted upon the bracket S, the disk D may be moved transversely to the motor-shaft. In this instance the brushes are rotatable relatively to the disk D, but it is obvious that other equivalentconstructions might be used, and the invention is not limited to a construction in which the brushes are rotatable.

vconductingstrips O, P, Q, and R.

The disk D is comprised of several parts and forms a composite structure. As shown more particularly in Fig. 4, the conducting plates I and J and other conducting parts of the disk are secured to the metallic backingplate Y. Suitable insulated screws Z secure the plates to the backing, While another screw at is in electrical contact with the plate J of the disk D and carries a brush 1), adapted to bear upon the contacts 0, Fig. 6, as will hereinafter appear. The screw a is suitably insulated from the metallic plate Y. Suitable insulation is arranged between the backing-plate Y and the plates I and J, in this instance layers of mica or fiber being arranged between said plates.

In Fig. 5, d represents a resistance-box provided with the resistances e,f, g, h, and t', which are connected, respectively, by the wiresj between the plates I and J and the It will thus be seen that the plate I is electrically connected through the entire resistance-box d with the plate J. In connecting the apparatus in circuit electrical connection is made from the positive lead--for instance, to the plate J-by means of the contact-screw a, while suitable electrical connection is made from the negative lead to the binding-posts upon the plate I. According to the construction of the disk D as described and arrangement of circuits it will be seen that if two of the brushes E bridge the plates 1 and J a circuit will be completed around resistance-box d, but when the same two brushes both bear upon the plate J the circuit is completed through the entire resistance in the box d, which resistance should be so great that practically no current can flow, and if a motor were connected in circuit insufficient current would flow to operate the motor.

Two pairs of brushes are used in the apparatus to increase the efficiency and evenness of operation, although it is obvious that only one pair of brushes may be used, if desired. The strips L between the plates I and J have no function as conductors, but are embedded in the resistance K to aiiord wearing-surfaces. The brushes rotate clockwise in the direction of the arrow 0, Fig. 5, and it will be seen that maximum current flows as long as the plates I and J are bridged by one of the pairs of brushes, and as one of the brushes of a pair passes from the plate I to the plate J the resistances 6,]'', g, h, and t' are included in circuit one after another, although the circuit is never broken. By thus avoiding an actual break in the circuit all the evils of sparking are avoided, so that this apparatus is particu larly applicable for use on inductive circuitsas, for instance, for operating an electric motor.

Any suitable brushes E may be used with the device; but, as shown, carbon brushes are supported in the brass sleeves p, carried in the holders H. Between the sleeves p and the disk D are arranged the washers or collars q, of refractory material. The sleeves p are suitably held in place by spring-pressu re, as shown, the spring 0* being provided for this purpose.

Means are provided for diminishing the full value of the current in the circuit as the length of the time intervals during which maximum current flows decreases. In this instance resistance 8 is gradually included in circuit as the disk D is moved in a direction to decrease the said time interval. The disk D may be moved so far to the right, looking at Fig. 5, that all the brushes E rotate constantly in contact with the plate J only, in which case the current is not varied, and with the disk in such position the whole of resistance s will be included in circuit, and thus as the disk D is moved to the right to afford a shorter and shorter arc of contact with the plate I the resistance sis gradually included in circuit. The object of providing the resistance s is to afford better means of regulation, more especially with inductive circuits, although the additional resistance 3 finds its uses upon non-inductive circuits. I/Vhen the regulator is connected to a motor, for instance, the counter electromotive force of the motor will decrease, due to the decrease of the speed of the armature as the duration of the time intervals during which maximum current flows is decreased. The resistance 8 is thus gradually thrown into circuit to keep the current in the motor substantially constant with all speeds.

The details of the brush-holder for the brush 5 are shown more particularly in Fig. 3. The carbon brush b is held in the metallic holder If, which is recessed at one side to permit the springs to to press the brush tightly against the side of the holder. Another spring 1) presses the brush against the contacts c, which are suitably insulated from each other and connected by the insulated screws w to the metallic base 00. Wires y connect the resistance 5 to the binding-screws 2, fastened to the contacts 0.

Obviously some features of the invention may be used without others, and the invention may be embodied in widelyvarying forms.

'Iherefore,without limiting, the invention to the construction shown and described nor enumerating equivalents, I claim, and desire to obtain by Letters Patent, the following:

1. In a current-regulator, the combination of means for varying the duration of the time intervals during which maximum current flows, and means for progressively including resistance in circuit without breaking circuit, after maximum current is permitted to how.

2. In a current-regulator, the combination of means for intermittently sending maximum currents through a circuit at predetermined intervals, means for varying the duration of the time intervals during which maxi- TOP mum currents flow, and means for gradually varying the resistance of the circuit without breaking the circuit after maximum current has been permitted to flow, for substantially the purposes set forth.

3. In a current-regulator, the combination of means for intermittently sending maximum currents through a circuit at predetermined intervals, means for varying the duration of the time intervals during which maximum currents flow, and means for progressivelyincluding resistance in circuit without breaking the circuit after maximum current has been permitted to flow, for substantially the purposes set forth.

4. In a current-regulator, the combination of means for intermittently sending currents of predetermined value through a circuit, means for varying the duration of the time intervals during which said currents flow, and means for gradually including resistance in the circuit without breaking the circuit after the current of predetermined value has been permitted to flow for a given time for substantially the purposes set forth.

5. In a current-regulator, the combination of means for varying the duration of the time intervals during which currents of predetermined strength fiow in a circuit, and means for including resistance in circuit as the length of the said time intervals decreases.

6. In a current-regulator, the combination of means for varying the duration of the time intervals during which currents of predetermined strength flow in a circuit, and means for varying the resistance of the circuit with the duration of the time intervals.

'7. In a current-regulator, the combination of means for intermittently sending currents of given strength through a circuit, means for varying the duration of the time intervals during which said currents flow, and means for automatically increasing the resistance of the circuit as the length of the time intervals decreases. Y

8. In a current-regulator, the combination of means for varying the duration of the time intervals during which currents of predetermined strength fiow through a circuit, and means for diminishing the full value of the current in the circuit as the duration of the said time intervals decreases.

9. In a current-regulator operating with intermittent currents, the combination of means for sending intermittently through a circuit currents of given strength, means for varying the time intervals during which said currents are permitted to flow, and means for including resistance in circuit step by step as the current strength is changed from one value to another without breaking the circuit, whereby sparking is avoided.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GEORGE ALEXANDER OAR-DWELL.

Witnesses:

H. G. OGDEN, Jr., A. L. OBRIEN. 

